203 



The very terra decomposition ^implies, in my view 

 of the subject, the entire reduction of a rock or other 

 mineral substances, in whole or in part, to its integrent 

 moleculae ; at least so far as to be susceptible of being 

 carried away by the winds, rains, &c. 



* It may not be amiss to observe, that the word decomposition,. in 

 this instance, is taken or used in a limited sense, that is, as differ- 

 ing in some degree from that of disintegration. 



For example, a rock or mass of imperfectly formed gneiss, gra- 

 nular lime-stone, dolomite, or sand stone, falling into small grains, 

 may be said to have undergone the process of disintegration. But 

 if the felspar which forms a constituent part of the gneiss, should 

 fall into an impalpable powder or paste like substance, as is the 

 case with petunze, when changed into kaolin, it may be said to 

 have undergone a partial decomposition. 



The decomposition of a substance, is a very common expres* 

 sion made use of to denote the wasting or gradual disappearance 

 of some earthy or mineral substances. But the word decomposed, 

 (whence decomposition) technically used, implies the resolving or 

 dissolving of a mixed body, or in other words, the reduction of 

 a body or substance, by some chemical or other process, to its 

 elementary principles. 



Hence, it would never answer to be applied, in its full extent, in 

 the destruction of mountains, the disintregration of rocks, or the 

 wasting away and disappearance of earthy and mineral substances 

 by which the common soil whence we derive our subsistence, is form- 

 ed ; for the integrant moleculae of rocks, and of which we will sup- 

 pose our soil to be composed, being alike subject to the operations 

 of the same agent, would likewise be reduced to the elementary 

 princi pies, and we should have no soil at all. 



This fact ought to be kept in view by those who so strenuously 

 advocate the perpetual decomposition or utter wasting away of the 

 solid materials, of which the crust of this globe is composed 5 an 

 opinion as absurd and inconsistent, as unphilosophical. 



